Heat oven to 350 degrees F. Line a 15 x 10-inch jellyroll pan with wax paper.
Prepare cake mix as directed on box except spread half of the batter into
pan. Spread remaining batter into an ungreased 9 x 5-inch loaf pan.
Bake until top springs back when touched lightly in center, jellyroll pan
for 20 to 25 minutes - loaf pan for 45 to 50 minutes.
Cool jellyroll pan for 10 minutes.
Loosen cake from edges of pan; invert onto towel sprinkled with confectioners'
sugar. Carefully remove wax paper. Trim off stiff edges if necessary. While
hot, carefully roll cake and towel from narrow end. Cool on wire rack. Invert
loaf pan to cool.
Remove cake from pan; freeze for future use.
Unroll cake; remove towel. Beginning at narrow end, spread raspberry sherbet
on 1/3 of cake, orange sherbet on next 1/3 of cake, and lime sherbet on remaining
cake. Roll up carefully. Place roll, seam side down, on an 18 x 12-inch length
of aluminum foil. Wrap securely in foil; freeze until firm, at least 6 hours.